UC Riverside

With increasing alterations to disturbance regimes, understanding recovery mechanisms is vital to prevent habitat degradation. Plant traits can link responses from individuals across multiple levels of ecological processes to predict community recovery, but this may be contingent on selecting the right trait at the right life stage and scale of environmental gradient or the diversity of traits and functional strategies. Regeneration traits (early life stage traits), which often differ from adult traits, may be more indicative of successful establishment post-disturbance, yet are not used to predict recovery or used in restoration of degraded habitats. Therefore, I aimed to assess how regeneration traits mediate post-fire recovery and restoration in chaparral shrublands. I asked 1) how regeneration and adult traits differ and which is more predictive of recovery, 2) how spatial scale influences trait filtering and variation at different life stages, and 3) how regeneration trait functional strategies and restoration timing influence restoration success. To assess life stage trait differences, I collected functional traits for regenerating plants within multiple burn scars and for adults in nearby unburned areas in Southern California. To link traits to recovery, I measured community composition and survival over multiple years. To test the influence of spatial scales, I used the trait same sampling design across a regional scale elevation gradient and local scale aspect. To test chaparral restoration methods, I planted shrubs with different regeneration trait functional strategies (i.e., acquisitive, conservative, diverse) into burn scars at different times since fire. I found regeneration traits were more resource-acquisitive than adult traits, and the functional diversity of regeneration traits, but not adult traits, predicted recovery (Q1). Regeneration traits were more strongly filtered at the regional scale and had different drivers of trait variation compared to adults (Q2). The conservative regeneration trait functional strategy had higher survival one year post-planting, and planting sooner after fire improved restoration success (Q3). Overall, this work first highlights how regeneration traits can be used to improve recovery predictions, then provides experimental evidence to improve post-fire restoration outcomes using a trait-based approach.